Machine learning for ultra high throughput screening of organic solar cells: Solving the needle in the hay stack problem

TL;DR

This paper introduces a machine learning method that rapidly analyzes organic solar cell data, enabling quick characterization and data mining to accelerate material discovery and improve understanding of device performance.

Contribution

A novel machine learning technique that efficiently extracts key parameters from JV curves, significantly speeding up analysis and facilitating data-driven material discovery in organic solar cells.

Findings

Reduces analysis time from weeks to seconds.

Enables characterization of new devices during fabrication.

Facilitates data mining of historical datasets for promising materials.

Abstract

Over the last two decades the organic solar cell community has synthesised tens of thousands of novel polymers and small molecules in the search for an optimum light harvesting material. These materials were often crudely evaluated simply by measuring the current voltage curves in the light to obtain power conversion efficiencies (PCEs). Materials with low PCEs were quickly disregarded in the search for higher efficiencies. More complex measurements such as frequency/time domain characterisation that could explain why the material performed as it did were often not performed as they were too time consuming/complex. This limited feedback forced the field to advance using a more or less random walk of material development and has significantly slowed progress. Herein, we present a simple technique based on machine learning that can quickly and accurately extract recombination time constants and charge carrier mobilities as a function of light intensity simply from light/dark JV curves alone. This technique reduces the time to fully analyse a working cell from weeks to seconds and opens up the possibility of not only fully characterising new devices as they are fabricated, but also data mining historical data sets for promising materials the community has over looked.